What Is Runner’s Knee?
Runner’s knee is the term doctors use for a number of specific conditions affecting the knee, such as patellofemoral pain syndrome and chondromalacia of the patella, to name just two. It’s the most common overuse injury among runners, but it can also strike other athletes who do activities that require a lot of knee bending, such as biking, jumping, or skiing.
Runner’s knee happens when the kneecap (patella) tracks incorrectly over a groove in the thighbone (femur) known as the femoral groove when you bend and straighten your knee. In healthy knees, the patella rests in the femoral groove and slides easily up and down when you use your knee. But when the patella is out of place, it can irritate the femoral groove and wear away the cartilage beneath the patella, leading to knee pain.
Symptoms of Runner’s Knee
The most common symptom of runner’s knee is tenderness or pain behind or on the sides of the patella, usually toward the center or back of the knee where the thighbone and kneecap meet. In addition, the knee might be swollen.
The pain will generally feel worse when bending the knee — when walking, kneeling, squatting, or running, for example. Walking or running downhill or even down a flight of steps also can lead to pain if someone has runner’s knee. So can sitting for a long period of time with your knee bent, such as in a movie theater.
In some cases, someone with runner’s knee may notice a popping or cracking sensation in the knee, as well as a feeling that the knee may be giving out.
If it goes untreated for a long period of time, runner’s knee can damage the cartilage of the knee and hasten the development of arthritis.
How Is Runner’s Knee Diagnosed?
If you see a doctor about pain in your knee, he or she will review your medical history and ask you questions about your symptoms and the activities you are involved in. Be sure to tell your doctor if you’ve increased how much time you spend at a certain activity or how often you do it.
The doctor will probably check the alignment of your kneecap, thigh, and lower leg, as well as look at your range of motion. Your doc will also check your kneecap for signs of tenderness or dislocation. You may be asked to squat, jump, or lie down so your doctor can assess your knee’s strength and mobility.
In some cases, your doctor may order imaging tests like an X-ray or MRI to see if there is any damage to the structure of your knee or the tissues connected to it.
What Causes Runner’s Knee?
Runner’s knee can happen for a variety of reasons, many of them having to do with the muscles and bones of the leg. Some of the more common causes are:
- Direct trauma to the knee. Falling on your knee or taking a blow to the knee can dislocate the patella or move it out of place, causing it to track incorrectly along the femoral groove.
- Excessive training or overuse. Repeatedly bending and flexing the knee can irritate the nerves around your kneecap and strain your tendons to the point of discomfort.
- Misalignment of the patella. If your kneecap is out of alignment, activities like running or biking can wear down the cartilage of the kneecap (chondromalacia of the patella), which can lead to pain and irritation in the underlying bone and joint lining.
- Tight or weak leg muscles. Tight hamstrings and calf muscles can put excessive pressure on the knee when you run, and weak quadriceps muscles can result in misalignment of the kneecap.
- Foot problems. Flat feet, also called fallen arches or overpronation, can stretch the muscles and tendons of your leg and lead to pain in the knee.
Preventing Runner’s Knee
The good news about runner’s knee is that you can take precautions to protect yourself against it. If you’re going to be doing an activity that puts a lot of stress on your knees, follow these tips:
- Warm up and stretch before running or doing any other knee-intensive activity, and be sure to stretch again after you’re done. Keeping your leg muscles strong and flexible will allow them to support the knee better and make it less likely to be irritated during exercise.
- Keep yourself in good shape. The heavier you are, the more weight your knees will have to bear with every step you take. By keeping your weight in check, you can minimize the stress on your knees and decrease the likelihood of pain